Cities can be considered complex systems, constantly changing
and adapting to new economic, social, and cultural dynamics. They exist in
many forms and over a wide range of sizes. In spite of this, researchers have
discovered regularities in the form of simple scaling laws that emerge when
urban outputs of many types, such as income, patents or energy consumption,
are correlated with population size. This article briefly presents some facts
and figures on scaling correlations in urban contexts and how this evidence
can determine and influence the obsolescence of energy infrastructures. It
finally suggests several strategies which could be used to ameliorate the
impacts of this performance in urban consumption forecasting assessment
processes.

Through the history of Electrical Engineering education, vectorial and phasorial diagrams have been used as a fundamental learning tool. At present, computational power has replaced them by long data lists, the result of solving equation systems by means of numerical methods. In this sense, diagrams have been shifted to an academic background and although theoretically explained, they are not used in a practical way within specific examples. This fact may be against the understanding of the complex behavior of the electrical power systems by students. This article proposes a modification of the classical Perrine-Baum diagram construction to allowing both a more practical representation and a better understanding of the behavior of a high-voltage electric line under different levels of load. This modification allows, at the same time, the forecast of the obsolescence of this behavior and line’s loading capacity. Complementary, we evaluate the impact of this tool in the learning process showing comparative undergraduate results during three academic years

Allometric scaling relations are characteristic of
all living organisms. Metabolic and heart rates, lifespan and
many other physiological properties vary with body mass in
systematic and interrelated ways, which usually take the form
of a power law. Scaling laws have been recently observed also
in the metabolic rate of a particular kind of living system: the
city. Scaling exponents of urban indicators present a remarkable
variability, mainly associated with fundamentally different underlying
dynamics. In this paper allometric scaling is used to detect
dissimilar behaviors in one particularly important urban indicator:
electricity consumption. Different scaling relations between
electricity consumption and economical and social sectors found
in southern Spain region of Andaluc´ıa, indicate variability in
these sectors’ basal energy consumption processes. The usefulness
of these findings for urban modeling is finally outlined and some
practical implications are suggested.